Ceiling-embedded air conditioner

ABSTRACT

An air passage has a blow-out side opening opposed to a position other than the longitudinal ends of a blow-out port of a decorative panel. The width of a louver, as determined in an air-blowing direction, decreases from a longitudinal center of the louver to the ends of the louver.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a Continuation Application of PCT Application No. PCT/JP2008/068819, filed Oct. 17, 2008, which was published under PCT Article 21(2) in Japanese.

This application is based upon and claims the benefit of priority from prior Japanese Patent Applications No. 2007-278133, filed Oct. 25, 2007; and No. 2007-278134, filed Oct. 25, 2007, the entire contents of both of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a ceiling-embedded air conditioner which regulates the blown-out air stream in such a manner as to uniformly air-condition the entire room, and which prevents condensation on the louver.

2. Description of the Related Art

This type of air conditioner comprises an air blower and a heat exchange unit provided in the unit casing. The rotation of the air blower causes the indoor air to be sucked from a suction port. The sucked indoor air is subject to the heat exchange by the heat exchange unit. The air flows through an air passage and is then blown into the room through a rectangular blow-out port.

A decorative panel is provided on the lower surface of the unit main body, and a suction port is provided in the center of the decorative panel. Blow-out ports are arranged along the sides of the decorative panel in such a manner that they surround the suction port, and a louver configured to change the blow-out direction is rotatably provided in each of the blow-out ports.

A drain pan is provided under the heat exchange unit described above. The drain pan is configured to receive a drain falling from the heat exchange unit, and the outer surface of the side walls define part of an air passage communicating with the blow-out port.

In the conventional art, air can be blown out of the blow-out port formed along each side of the decorative panel, but the air cannot be blown out of the corner portions of the decorative panel. Due to this, the temperature distribution in the room may not be uniform.

The air conditioner recently developed include an air conditioner wherein a blow-out port is formed in the corner portions of the decorative panel so that air can be blown out of the corner portions as well, and wherein a louver is provided in the blow-out port. (Refer to Jpn. Pat. Appln. KOKAI Publication No. 2005-249328.)

The air passing through the heat exchange unit and flowing along the air passage is under the influence of a centrifugal force. Therefore, the air flows along the inner wall surface of the air passage facing the outer surface of the side wall of the drain pan, before it reaches the blow-out port. Due to this, the quantity of air supplied is large in the region corresponding to the upper surface of the louver, and is small in the region corresponding to the lower surface of the louver. The quantity of air supplied is small especially in the region corresponding to longitudinal end portions of the lower surface of the louver. Since the quantity of air supplied is small in such regions, the indoor air, which is hot and humid, may flow into the regions, causing condensation on the louver.

The air conditioners recently developed include an air conditioner wherein the air is blown toward the lower surface of the louver so as to prevent the condensation on the louver, such as the air conditioner disclosed in Jpn. Pat. Appln. KOKAI Publication No. 8-94160.

BRIEF SUMMARY OF THE INVENTION

In the air conditioner disclosed in Jpn. Pat. Appln. KOKAI Publication No. 2005-249328, a blow-out port and a louver are added to the corner portions of the decorative panel. Hence, the air conditioner is disadvantageous in that it is complex in structure and requires a high manufacturing cost.

On the other hand, the air conditioner disclosed in Jpn. Pat. Appln. KOKAI Publication No. 8-94160 has problems in that the structure of the air passage is complex. Since the number of parts required is therefore large, the manufacturing cost is inevitably high.

The present invention has been made in consideration of the above circumstances, and an object of the invention is to provide a ceiling-embedded air conditioner which enables the air subjected to the air exchange to be blown into a room in every direction desired, without having to add a blow-out port and a louver to the corner portions of a decorative panel, and which prevents condensation at the end portions of the louver with a simple structure.

A ceiling-embedded air conditioner according to one aspect of the present invention comprises: a casing in which a heat exchange unit and an air blower are arranged; a decorative panel located on a lower side of the casing and including a suction port and a rectangular blow-out port; a rectangular louver rotatably provided inside the blow-out port and configured to change a blowing direction in which air is blown out from the blow-out port; and an air passage comprising a rectangular section and configured to guide indoor air, drawn in from the suction port by rotation of the air blower, to the heat exchange unit for heat exchange, and then guide the indoor air to the blow-out port, the air passage comprising a blow-out side opening opposed to a position other than longitudinal ends of the blow-out port, and the width of the louver, as determined in the blowing direction, decreases from a longitudinal center of the louver to ends of the louver.

A ceiling-embedded air conditioner according to another aspect of the present invention comprises: a casing in which a heat exchange unit and an air blower are arranged; a decorative panel located on a lower side of the casing and including a suction port and a rectangular blow-out port; a rectangular louver rotatably provided inside the blow-out port and configured to change a blowing direction in which air is blown out from the blow-out port; an air passage comprising a rectangular section and configured to guide indoor air, drawn in from the suction port by rotation of the air blower, to the heat exchange unit for heat exchange, and then guide the indoor air to the blow-out port; a drain pan provided on a lower side of the heat exchange unit and defining part of an air passage communicating with the blow-out port; and a projection projected upward'from an upper portion of the drain pan and located in an upper region of end portions of the blow-out port.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

FIG. 1 is an exploded perspective view showing the indoor unit of a ceiling-embedded air conditioner according to one embodiment of the present invention.

FIG. 2 is a sectional view showing the indoor unit depicted in FIG. 1.

FIG. 3 is a view of a decorative panel of the indoor unit depicted in FIG. 2.

FIG. 4 is a perspective view of a louver provided in a blow-out port of the decorative panel.

FIG. 5 is a plan view illustrating how the louver depicted in FIG. 4 is provided in the blow-out port of the decorative panel.

FIG. 6 is a perspective view showing how the air guided by the louver depicted in FIG. 4 flows.

FIG. 7 shows how the air blown out of the indoor unit depicted in FIG. 2 flows.

FIG. 8 is a view of a louver provided in a blow-out port of the decorative panel depicted in FIG. 3.

FIG. 9 shows the dimensional relationships between the blow-out port of the decorative panel and a drain pan dent section.

FIG. 10 is a view of an air-guiding depressed section formed in the decorative panel depicted in FIG. 3.

FIG. 11 is a view of a louver and a blow-out port employed in another embodiment of the present invention.

FIG. 12 is a view of a decorative panel employed in the second embodiment of the present invention.

FIG. 13 is a perspective view of a drain pan employed in the second embodiment of the present invention.

FIG. 14 shows how the air flows into an air passage from the drain pan depicted in FIG. 13.

FIG. 15 shows how the air flows when it is blown out along the outer surface of the side wall of the drain pan depicted in FIG. 13.

FIG. 16 shows how the air flows when it is blown out along the upper surface and the lower surface of the louver depicted in FIG. 1.

FIG. 17 is a perspective view of part of a drain pan employed in still another embodiment of the present invention.

FIG. 18 shows how the air flows into a passage from the drain pan depicted in FIG. 17.

FIG. 19 shows how the air flows where no projection is formed on the upper surface of the drain pan depicted in FIG. 17.

DETAILED DESCRIPTION OF THE INVENTION

A description will now be given of embodiments of the present invention with reference to the accompanying drawings.

First Embodiment

FIG. 1 is an exploded perspective view of an indoor unit 1 of a ceiling-embedded air conditioner according to one embodiment of the present invention. FIG. 2 shows a state in which the indoor unit 1 is provided in a ceiling 11.

The indoor unit 1 comprises a casing 1 a. A turbo fan 3, serving as an air blower, is provided substantially in the center of the casing 1 a. An indoor heat exchange unit 2 surrounds the outer periphery of the turbo fan 3. A drain pan 4 is provided on the lower side of the indoor heat exchange unit 2. A drain pan dent section 4 a is formed in each outer side wall of the drain pan. The drain pan dent section 4 a communicates with a blow-out port 12 provided in a decorative panel 5 (to be described later) and constitutes part of an air passage 20.

A decorative panel 5 is provided on the lower side of the casing 1 a. A suction grille 7, serving as a suction port, is located substantially in the center of the decorative panel in such a manner that the suction grille 7 faces the turbo fan 3, with a certain distance maintained from it. A filter 8 is provided on the upper side of the suction grille 7.

As shown in FIG. 3, blow-out ports 12, which are rectangular in shape, are formed in the respective four sides of the decorative panel 5 in such a manner that the blow-out ports surround the suction grille 7. The blow-out ports 12 communicate with the suction grille 7 through the air passage 20. A louver 14 configured to change the air blowing direction is provided in each of the blow-out ports 12.

With the above structure, when the turbo fan 3 rotates, the indoor air is sucked in through the suction grill 7 of the decorative panel and the filter 8. The sucked air flows through the air passage 20 and is guided to the indoor heat exchange unit 2. When the air passes through the heat exchange unit 2, it is subjected to heat exchange. After the heat exchange, the air passes through the drain pan dent sections 4 a into the blow-out ports 12 of the decorative panel 5, and is then blown out into the room.

The louver 14 has a rectangular shape, as shown in FIG. 4. The width of the louver 14 gradually decreases from the central portion 14 a to the longitudinal ends 14 b (the widthwise direction of the louver 14 is a direction in which the air is blown out). Pin members 14 c are projected from the respective ends of the louver 14.

The louver 14 is attached by rotatably fitting the pin members 14 c in attachment holes (not shown), which are formed in the inner walls located at the ends of the blow-out port 12. As shown in FIG. 5, the width h of the central portion 14 a of the louver 14 is 80% or more of the width H of the blow-out port 12.

A closure members 10, such as a block or a wind shielding plate, is provided at each longitudinal end of the blow-out port 12. The air guided to the ends of the blow-out port by the louver 14 is prevented from flowing downward (into the living space) by the closure member 10. In this manner, cold draft is prevented.

The louver 14 has such a structure as described above. When the louver 14 is rotated and kept in the horizontal state (at an angle corresponding to a slightly closed state), the gap between the louver 14 and the blow-out port 12 is greater at the end portions 14 b of the louver 14 than at the center portion 14 a.

As shown in FIG. 6, the air blown out from the air passage 20 into the blow-out port 12 is guided not only forward but also toward the ends of the louver 14 (in the longitudinal direction). As a result, the air is blown out not only at the four sides of the decorative panel 5 but also at the corners, as indicated by arrows 13 in FIG. 7. In this manner, the air can be blown out in a wide range, and the entire room can be air-conditioned uniformly with a simple structure.

When the louver 14 is rotated and kept in a substantially horizontal state, that portion of the louver 14 which is located downstream in the blow-out direction is projected down from the lower end 12 a of the blow-out port 12. The projected portion is approximately more than two fifths of the width of the louver 14. In this state, the ends 14 b of the louver 14 are projected downward from the lower end 12 a of the blow-out port 12.

With this feature, the air can flow forward in a more reliable manner, and at the same time it can be guided in a lateral direction of the louver (in the longitudinal direction).

As shown in FIG. 9, the longitudinal dimension of the drain pan dent section 4 a at the lower end 4 b, which defines a blow-out side opening of the air passage 20, is less than the longitudinal dimension of the blow-out port 12. With this structure, the air flowing through the longitudinal ends of the drain pan dent section 4 a moves along the lower end wall 4 c of the drain pan, as indicated by an arrow, and can therefore be guided toward the longitudinal ends of the blow-out port 12.

As shown in FIGS. 9 and 10, depressed sections 5 a are formed in the respective inner wall portions at the longitudinal ends of the blow-out port 12 of the decorative panel 5. The depressed sections 5 a surround the periphery of the suction grille 7. With this structure, the air blowing out from the longitudinal ends of the blow-out port 12 is smoothly guided by the depressed sections 5 a and flows toward the corners of the decorative panel 5.

Second Embodiment

FIG. 11 shows the second embodiment of the present invention.

In the first embodiment described above, the width of the louver 14 gradually decreases, from the central portion 14 a to the longitudinal ends 14 b. In the second embodiment, the width of a blow-out port 21 increases from the central portion to the longitudinal ends. A louver 22 having a constant width in the longitudinal direction thereof is arranged in the blow-out port 21. A wind-shielding plate 23 configured to prevent the flow-out air from falling down is provided at each end of the blow-out port 21.

In the second embodiment, when the louver 14 is rotated and kept in the horizontal state (at an angle corresponding to a slightly closed state), the amount of wind coming from the central portion of the blow-out port 21 is decreased, and the amount of wind coming from the end portions is increased. In this manner, the air can be guided laterally and blown out from the end portions of the louver 14, and the second embodiment provides advantages similar to those of the first embodiment.

As shown in FIG. 12, the decorative panel 5 may have cut-out sections 5 b extending in a predetermined direction of a side frame. In this case, the air guided by the depressed sections 5 a is made to flow in the predetermined direction by the cut-out sections 5 b.

With this structure, the air can be reliably blown in a lateral direction or in an oblique direction, which was hard to attain in the conventional art.

Third Embodiment

FIGS. 13-16 show the third embodiment of the present invention.

FIG. 13 is a perspective view showing part of a drain pan 4, and FIG. 14 is a sectional view of a side portion of the drain pan 4.

A pair of projections 25, which are projected upward, are formed on the upper surface of a side wall of the drain pan 4, with a predetermined distance kept away from each other. The paired projections 25 are located in the upper region of the end portions of a blow-out port 12. The upper surface and the inner wall surface of the drain pan 5 are coated with resin 13, and the projections 25 are integrally formed of resin 13.

Part of the air that has been subjected to heat exchange by the heat exchange unit 2 rises along the inner wall surface of the drain pan 4, as shown in FIG. 14. When the rising air reaches the upper surface of the side wall of the drain pan 4, the air in the center flows in a horizontal direction and enters a drain pan dent section 4 a, as indicated by arrow a. The air at the ends continues to rise along the inner surfaces of the projections 25, as indicated by arrows b, and then flows into the drain pan dent section 4 a, as shown in FIG. 14.

As indicated by the air stream shown in FIG. 14, a negative pressure is generated in the regions located in the vicinity of the outer walls of the projections 25, causing an eddy air flow. Because of the eddy air flow, the air stream along the longitudinal ends of the drain pan dent section 4 a flows in proximity of the upright wall surface 4 c of the drain pan dent section 4 a, as shown in FIG. 15, and then flows in proximity of the inner wall surface of the blow-out port 12, as shown in FIG. 16.

Because of this, the speed of the air flowing along the upper surface at the longitudinal ends of the louver 14 is decreased, and the speed of the air flowing along the lower surface at the longitudinal ends of the louver 14 is increased.

As a result, the temperature in the region corresponding to the upper surface of the louver 14 and the temperature in the region corresponding to the lower surface of the louver 14 become substantially equal to each other. Hence, the condensation at the specific portion of the louver 14 can be suppressed with a simple structure, without the need to perform hair implantation at that portion.

As shown in FIG. 3, the louver 14 has cut-out sections 4 e at the longitudinal ends in such a manner that the cut-out sections 4 e are located upstream in the blowing direction. The cut-out sections 4 e permit the blown-out air to flow smoothly into the region corresponding to the lower surface of the louver 14. Accordingly, the condensation at the end portions of the louver 14 can be suppressed more reliably.

Fourth Embodiment

FIGS. 17 and 18 show the fourth embodiment of the present invention.

In the third embodiment, the projections 25 are formed on the drain pan 4 to regulate the flowing direction of the blown-out air. In the fourth embodiment, the drain pan 4 comprises angular portions 26 a at the end portions on the upper surface of the side wall, and a curved portion in the center portion thereof.

As shown in FIG. 18, part of the air that has subjected to heat exchange by the heat exchange unit 2 rises along the inner wall surface of the drain pan 4, as shown in FIG. 18. When the rising air reaches the upper portion of the side wall of the drain pan 4, the air in the center flows in a horizontal direction and enters a drain pan dent section 4 a, as indicated by' arrow a. The air at the ends continues to rise along the angular portions 26 a, as indicated by arrows b, and then flows into the drain pan dent section 4 a, as shown in FIG. 18.

As indicated by the air stream shown in FIG. 18, a negative pressure is generated in the regions 18 located in the vicinity of the upper end portions of the side wall of the drain pan 4, causing an eddy air flow. Because of the eddy air flow, the air stream along the longitudinal ends of the drain pan dent section 4 a flows in proximity of the upright wall surface 4 c of the drain pan dent section 4 a, as shown in FIG. 18, and then flows in proximity of the inner wall surface 12 a of the blow-out port 12, as shown in FIG. 16.

Because of this, the speed of the air flowing along the upper surface at the longitudinal ends of the louver 14 is decreased, and the speed of the air flowing along the lower surface at the longitudinal ends of the louver 14 is increased.

As a result, the temperature in the region corresponding to the upper surface of the louver 14 and the temperature in the region corresponding to the lower surface of the louver 14 become substantially equal to each other. Hence, the condensation at the specific portion of the louver 14 can be suppressed with a simple structure, and the louver 14 need not comprise hair implanted thereon.

FIG. 19 shows how the blown-out air flows when the drain pan 4 does not comprise angular portions 26 a at the end portions on the upper surface of the side wall.

In this case, the air stream into the drain pan dent section 4 a does not cause an eddy air flow. Thus, the blown-out air flows into the blow-out port 12 in proximity of the inner wall surface 20 facing the upright wall surface 4 c of the drain pan dent section 4 a.

Because of this, the speed of the air flowing along the upper surface of the louver 14 is increased, and the speed of the air flowing along the lower surface of the louver 14 is decreased. As a result, the temperature in the region corresponding to the upper surface of the louver 14 and the temperature in the region corresponding to the lower surface of the louver 14 do not become substantially equal to each other. Hence, the condensation of the louver 14 cannot be suppressed.

The present invention is not limited to the embodiments described above. When the present invention is embodied, the structural elements can be modified without departing from the spirit and scope. In addition, various inventions can be created by properly combining the structural elements disclosed in relation to the embodiments described above. Some of the above-mentioned structural elements of the embodiments may be omitted. Furthermore, the structural elements of different embodiments may be combined together.

In the present invention, the width of the louver 14 is gradually decreased from the central portion 14 a to the longitudinal ends 14 b. Since the air can be blown out not only at the four sides of the decorative panel 5 but also at the corners, the entire room can be air-conditioned uniformly with a simple structure.

A pair of projections 25 are projected upward from the upper surface of the side wall of the drain pan 4, with a predetermined distance kept away from each other. With this simple structure, the speed of the air stream 16 along the lower surface of the louver 14 is increased at the longitudinal ends, in such a manner that the temperature in the region corresponding to the upper surface of the louver 14 and the temperature in the region corresponding to the lower surface of the louver 14 become substantially equal to each other. Hence, the condensation at the specific portion of the louver 14 can be suppressed with a simple structure, without the need to perform hair implantation at that portion. 

1. A ceiling-embedded air conditioner comprising: a casing in which a heat exchange unit and an air blower are arranged; a decorative panel located on a lower side of the casing and including a suction port and a rectangular blow-out port; a rectangular louver rotatably provided inside the blow-out port and configured to change a blowing direction in which air is blown out from the blow-out port; and an air passage comprising a rectangular cross section and configured to guide indoor air, drawn in from the suction port by rotation of the air blower, to the heat exchange unit for heat exchange, and then guide the indoor air to the blow-out port, the air passage comprising a blow-out side opening opposed to a position other than longitudinal ends of the blow-out port, a width of the louver, as determined in the blowing direction, decreases from a longitudinal center of the louver to ends of the louver.
 2. The ceiling-embedded air conditioner according to claim 1, wherein at least a downstream portion of the louver with respect to the blowing direction is projected downward from the blow-out port when the louver changes the blowing direction of the air to a horizontal direction.
 3. The ceiling-embedded air conditioner according to claim 1, wherein the suction port is provided in a central portion of the decorative panel, and the blow-out port is provided at four positions surrounding the suction port.
 4. A ceiling-embedded air conditioner comprising: a casing in which a heat exchange unit and an air blower are arranged; a decorative panel located on a lower side of the casing and including a suction port and a rectangular blow-out port; a rectangular louver rotatably provided inside the blow-out port and configured to change a blowing direction in which air is blown out from the blow-out port; an air passage comprising a rectangular cross section and configured to guide indoor air, drawn in from the suction port by rotation of the air blower, to the heat exchange unit for heat exchange, and then guide the indoor air to the blow-out port; a drain pan provided on a lower side of the heat exchange unit and defining part of an air passage communicating with the blow-out port; and a projection projected upward from an upper portion of the drain pan and located in an upper region of end portions of the blow-out port.
 5. The ceiling-embedded air conditioner according to claim 4, wherein the louver comprises cut-out sections at longitudinal ends such that the cut-out sections are located upstream in the blowing direction. 